$\dfrac{1}{5} + \dfrac{3}{4} = {?}$
Explanation: ${\dfrac{1}{5}}$ ${\dfrac{3}{4}}$ $+$ ${\dfrac{1 \times 4}{5 \times 4}}$ ${\dfrac{3 \times 5}{4 \times 5}}$ $+$ ${\dfrac{4}{20}}$ ${\dfrac{15}{20}}$ $+$ $ = \dfrac{{4} + {15}}{20} $ $ = \dfrac{19}{20}$